The present invention relates generally to ultrasound imaging systems and, more particularly, to a beamforming system using analog random access memory (RAM) elements for use in an ultrasound imaging system.
Ultrasound imaging systems have been available for quite some time and are commonly used in nondestructive testing and medical applications. Medical ultrasound imaging allows the internal structure of the human body to be viewed non-invasively in real time. The ultrasound imaging system may be capable of either two or three-dimensional imaging.
Ultrasound imaging systems include, among other elements, an ultrasonic probe (including an ultrasonic transducer array), processing and control electronics (including transmit and receive beamformers), a display, and cabling that connects the ultrasonic probe to the processing and control electronics. Ultrasonic transducers are typically configured in either one-dimensional or two-dimensional arrays. A one dimensional transducer array includes one row of ultrasonic transducer elements arranged longitudinally. A two dimensional ultrasonic transducer array typically includes ultrasonic transducer elements arranged in columns and rows.
Regardless of the transducer array arrangement, during transmit pulses, electrical energy is converted by the transducer element to acoustic energy and transmitted in the direction of a target. The acoustic energy reflects from the target and returns to the transducer element. The acoustic energy received by the transducer element is converted to an electrical signal and passed as a receive signal to the receive processing circuitry associated with the ultrasound imaging system. A typical two-dimensional ultrasonic transducer array includes many hundreds or thousands of individual transducer elements. The electrical signal supplied by each transducer element is multiplexed to a smaller number of channels and then coupled to the processing circuitry.
When acoustic energy is received by each transducer element, it is often desirable to alter the characteristics of the signal to improve the ultrasonic image. One such manner for altering the signal is to delay the signal in one channel with respect to other channels. This is commonly referred to as beamforming. By using beamforming, components of the receive signal may be altered to improve the displayed ultrasound image. Conventional beamforming techniques typically use multiple beamforming elements that use complex digital processing circuitry for each receive channel. Unfortunately, this requires complicated processing components and tends to increase the cost of the ultrasound system.
Therefore, it would be desirable to have a low cost and simple beamforming system for each channel in an ultrasound imaging system.
A simple, low cost ultrasound beamforming system uses an analog random access memory (RAM) element for each beamforming channel. The system includes a processor and an ultrasonic transducer array. The ultrasonic transducer array includes a plurality of transducer elements, each transducer element associated with one of a plurality of channels. The system also includes a beamformer adapted to receive an output signal from each of the plurality of transducer elements, and a delay element located in the beamformer and associated with each of the channels, where the delay element comprises an analog random access memory (RAM) element.
Other systems, methods, features, and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.